How is resistance wire used in a hair dryer?

A resistance wire in a hair dryer is used as the heating element to generate hot air. It works by converting electrical energy into heat through resistive heating (Joule heating effect).

How Resistance Wire Works in a Hair Dryer:

1. Electric Current Passes Through the Wire

• The resistance wire (usually made of nichrome—an alloy of nickel and chromium) resists the flow of electricity, causing it to heat up.

• Nichrome is used because it has high resistance, high-temperature durability, and doesn’t oxidize easily.

2. Heat Generation

• As the nichrome wire heats up, it radiates heat into the surrounding air.

• The wire is usually coiled to increase surface area and efficiency.

3. Airflow from the Fan

• A small electric fan inside the hair dryer pulls in ambient air and pushes it over the hot resistance wire.

• The air absorbs the heat and exits as hot air through the nozzle.

4. Temperature Control & Safety Features

• A thermostat or thermal fuse cuts power if the wire gets too hot, preventing overheating.

• Some hair dryers have multiple heat settings, adjusting the resistance or airflow to control temperature.

Why Nichrome is Used in Hair Dryers

• High electrical resistance → Heats up efficiently.

• Oxidation-resistant → Doesn't rust or degrade easily.

• High melting point (~1400°C/2552°F) → Safe for prolonged use.

This combination of heating and airflow makes hair dryers efficient at quickly drying hair. Are you looking to repair a hair dryer or build a heating element for a project?